Behavior of Letters when Grow

Hi All,

I got a Design-Theory-Problem that makes me real crazy …
I’d like to build a Font with two axes, width and weight.

Now I know when a letter becomes bolder > the x-heights with overhang grows a bit;
ascender, descender, cap-hight will stay at the same height.
My rule of thumb is here: the black want to displace the white to fill-in the cone (and vice versa)

But how acts the letter when become wider or narrower?
Is there some new behavior or have I to keep the vertical-proportions as they are?

Thx

I would keep the vertical proportions for different width. And for weight and width, change the vertical proportions only after checking in real world scenarios. I did several fonts where the xHeight is the same for light and bold.

I will do so. Its also more comfortable to keep the Masters in sync.

Thanks